CUCM 6.1.3 with LDAP Server using DNS name

John Tan · ‎11-25-2009

We have integrated CUCM 6.1.3 with our corporate LDAP Server using DNS

CUCM 6.1.3 LDAP Server is configured with DNS name of test.ldap.com and this DNS names resolves to 20 LDAP servers.

This has been working fine until we lost 1 LDAP Server and for 5 mins no one could log into CUCM using their windows credentials.

MY questions are

How does LDAP Server configured using DNS name work internally in CUCM 6.1.3?

1. Does CUCM keep a cache of the 20 LDAP Servers it keeps in its cache?

2. Does it keep just 1 LDAP Server in its cache?

3. If the LDAP Server that CUCM keeps in its cache is no longer avaliable, what does CUCM do? Does it try to re-resolve and go to the next LDAP Server?

4. How can we work around this issue using DNS name for the LDAP Servers?

htluo · ‎11-25-2009

DNS round-robin is used for load-balancing other than "fault-tolerance". Unless your DNS server can detect the failure of a host and remove its IP automatically.

If you want to achieve fault-tolerance, you should configured multiple LDAP Authentication entryies in CUCM.

Regards,

Michael

http://htluo.blogspot.com